Tachometer.



No. 826,630. PATENTED JULY 24, 1906. O. H. 'VEEDER.

TAGHOMBTER.

' APPLICATION FILED JULY 17,1905.

2 SHEETSSHEET 1.

Atte st': U Inventor:

QM 7 2 yw/wf V by 3 NO- 826,630. PYATENTED 611L224, 1906.

I c. H. VEEDER.

TAGHOMBTER.

APPLICATION FILED JULY17. 1905.

2 SHEETS-SHEET 2.

Invento? Vii/641A Ail UNITED STATES PATENT orrion'.

CURTIS H USSEY VEEDER, HARTFORD, CONECTICUT. TAC H O M E T E R Specification of Letters Patent.

Patented July 24, 1906.

Application filed July 17,1305. Serial No. 270,124.

To all whom it may concern.-

Be it known that I, CURTIS HUssEY VEE- DER, a citizen of the United States, residing in Hartford, in the county of Hartford, in the State of Connecticut, have'invented certain new and useful Improvements in Tachometers, of which the followin is a specification, reference being had to t e accompanying drawings, forming a part hereof.

This invention relates to devices or instruments for measuring the speed of shafts,

.wheels, &c., and of machines of various classes of the general character of the instruments shown and described inLetters Patent of the United States Nos. 732,975 and 733,358, both dated July 7, 1903, in which the speed is indicated by the difference in level of two 'c'o1nmunicating columns of liquid, or rather since reference is made to but one column, by the height of a column of liquid.

The object ofthe present invention is to so improve the construction of such instruments as to reduce the possibility of error under different conditions. Thus in the operation of the instruments referred to it has been found that the indication thereof was liable to vary when the paddle-wheel or shaft became eccentric or when there was any inequality or variation in the edges of the outlet-orifice of the pump-chamber or when there was endwise motionof the shaft. The liability to error from eccentricity of the shaft or paddlewheel and from a change in the direction of rotation and from inequality in the edges of the outlet is largely reduced or avoided altoether by providing a plurality of outlets from the pump-chamber, and the liability of error from endwise movement of the shaft is largely reduced by providing for the admission of fluid to the pump-chamber through 0 enings on both sides of the paddle-wheel. Tllese new features of construction involve substantial reconstruction of the pump and the devices immediately correlated therewith, all as will be more fully explained'hereinafter with reference to the accom anyingdrawings, in which the invention is illustrated. 1, In the drawings, Figure 1 is a view in front elevation of a tachometer constructed in accordance with the present invention. Fig. 2 is a vertical central section thereof in the plane of the pump-axis. Fig. 3 is a view in transverse Vertical section on the irregular filling-tube 0 tion of the tion-inlet,

planeindicated by the line 3 3 of Fig. 2. Figs. 4 and 5 are detail views of the plates which form the walls of the pump-chamber.

The construction of the indicating devices other than the pump and its correlated parts is substantially the same as shown and described in said Letters PatentNo. 733,358, and only brief reference thereto need'be had herein. The glass indicator-tube a is mounted upon a base I) and centrally with respect to the reservoir 0, the sides of which are preferably of glass and symmetrical with the axis of the ind icator-tube, sight-holes c being provided in the exterior metallic casin 0 The communicates at its ower end with the reservoir 0 and at its upper end through a bracket (1 with the indicator-tube a.

Obviouslythe indicating devices may be mounted either directly upon orbe connected indirectly with the pump-casing, and inthe accompanying drawings they are shown as mounted directly thereon. The pump in the present case also is shown as comprising a shell or casing e, a shaft f mounted therein, and blades or paddles g mounted on the shaft,

'the shaft being adapted to be connecte'd'mechanically in any suitable manner with the moving or actuating part. In the construction shown and described in said Letters Patent No. 733,358 the pump-chamber communicates through a single peripheral outlet with the indicator-tube a, and through an in lot at one side only with the reservoir 0. In thepresent instance, however, the casting e, which forms the bod of the pumpcasing, is formed with a chamber a, which communicates with the reservoir 0 through a channel and a regulating-chamber 'i and is separated from the pump-chamber proper by a disk 3;,- which is seated in the chamber of the casting a and is provided centrall with an opening e which communicates wlth the central porpump-chamber, forming the suc' and near its periphery with openings e, this plate forming one wall of the pump-chambe proper. A plate 6 forming the other wall 0 the pumpchamber proper, is flanged, as at e", to bear upon the late (3 and hold it in its seat, bein itself hel d in its seat by the cover-plate of t e pump shell or casing e. Th riphery with openings e to register with the e plate a Is provided near its pewill be observed, the p ate e preferably has a i tapered seat in the shell or casing e to form a tight joint.

The passage from the pump rovided, as in etters Patent 1, which conducts the liquid to the indicator-tube a, is the instrument described in No. 733,858, with a regulating-valve Z but in the present instance the pump-chamber on passage 1 does not communicate directly with the interior of the um chamber proper, but with an annu ar e amber l, which is'formed in the main art of the easing e and completely encirc es the plate e and its flange e". Through the flange e between the openings are formed holes e", distributed about the periphery of the pumpchamber proper and communicating with' the annular chamber Z at many different points, so that the liquid which enters the both sides through the suction-openings e and e escapes from the pump-chamber at many different ploints into the annular chamber Z, from whic it passes through the passage 1 to the indicator-tube a.

- The operation of the improved instrument is substantially the same, except as hereinbefore noted, as that scribed in said Letters Patent No. 733,358 and need not be further described herein. It will be observed that as the pump-chamber proper is rovided with a suction-inlet onea'c'h side the pump is balanced, and the effect of any endwise movement of the pumpshaft is very much reducedand the error 111 the instrument due to this cause is practically eliminated. Furthermore, as the pump discharges at numerous points about its periphery the effect of any variation or inequality-in any outlet-opening is likewise reduced, together with the chance of error,

and the pa dle can be considerably out of center andcan be rotated in either direction without chan ing the reading of the instrument. It wil be understood that in the operation of the indicator there should be no movement of the liquid between the reservoir and the 1pump except when the speed of rotation of t e impeller is increasing or decreasing and that the liquid in the ,passa e between the reservoir and the pump shou d not be disturbed or given any rotary movement, lest the pressure should be affected. Moreover, it will be understood that a very slight change in the height of the column of liquid in the indicator-tube must necessarily represent a considerable chan e in the speed of the pump-impeller. For t ese reasons it is necessary to guard with great care against of the instrument de any change in pressure and in height of the column of liquid in the indicator-tube except that which is due directly and solely to change In the use of indicating devices of this character in which theliquid is admitted to one side only'of the pump it has been found that the pressure at the periphery varied some.- what when the impeller or wheel was moved axially and that such variation in pressure developed and increased with the wear on the bearings. and to insure the-accuracy of the instrument after long continued use, it has been found desirable to provide connections from the reservoir to the pump on both sides thereof through openings a near the axis of the impeller, of restricted area, so that disturbance and rotary motion of the liquid in the passageare avoided, as well as any variation of pressure due to displacement of the impeller through Wear.

I claim as my invention 1. .A speed dicator comprising a rotating liquid-pump, anindicator-tube connected to the discharge of said pump, a reservoir, a connection from the reservoir to the indicator-tube above the liquid-level, and connections from the reservoir to the pum on both sides thereof through openings 0 restricted area near the axis of the' ump whereby variation of pressure throug displacement of the pump-impeller is avoided.

2. A speed-indicator comprisin a rotating liquid-pump having a plurality o discharge-openings, an indicating-tube con- To overcome this difiiculty in the speed of the pump-impeller.

peripheral IOO nected to all of said discharge-openings, a

reservoir and a connection from said reservoir to the suction of said pump, substantially as described.

3. A speed-indicator comprising a pump shell or casing, walls therein forming a pumpchamber and intercommunicating outer chambers, suction-openings being formed in said walls between the pump-chamber and said outer chambers, a rotating pumpwheel, an indicating-tube connected to the discharge of said pum and a reservoir connected to said outer c ambers,.substantially as described.

4. A speed-indicator comprising a pump shell or casing, a rotating liquid-pump disosed within said pump shell or casing and aving a plurality of eripheral dischargeopenings, an annular cfiamber being formed in said shell or casing and communicating with said peripheral openings, an indicatingtube connected to! 'said annular chamber,

and a reservoir connected to the suctionof said pump, substantially as described.

5. A speed-indicator comprising a pump shell or casing, a plate seated therein and having a central opening and openings near its periphery, a second plate set therein and flanged to form with the first plate a pump- I a reservoir connected to the suction of said chamber, a rotating pump-Wheel in said pump, substantially as described. 10

pump-chamber, said flange having aplurality TlllS specification signed and witnessed of peripheral openings therein, said shell or this 14th day of July, 1905.

casing having formed therein an annular CURTIS HUSSEY VEEDER. chamber about said flange communicating In presence of with said peripheral openings, an indicating- E. BARRIE SMITH,

tube connected to said annular chamber and E. G. BIDDLE. 

